Shallow M5.7 Earthquake struck on Friday Afternoon in the South Pacific Ocean 122km from Copiapó (Chile).

Written by Earthquakelist.org on September 15th, 2023. Last updated November 14th, 2023.

In the afternoon of Friday September 15th, 2023, a shallow and significant MAG-5.7 earthquake hit in the South Pacific Ocean 122 kilometer from Copiapó, Chile. Roughly 300 thousand people may have felt this earthquake.

Earthquake Summary

This earthquake hit under water in the South Pacific Ocean, 68 kilometers (42 mi) off the coast of Chile, 122 kilometer west of Copiapó in Atacama. The center of this earthquake had a very shallow depth of 5 km. Shallow earthquakes usually have a larger impact than earthquakes deep in the earth.

Date and Time:	Sep 15, 2023 15:07 (Santiago Time) - Sep 15, 2023 18:07 Universal Time.
Location:	122 km west of Copiapó, Atacama, Chile. Coordinates 27°18'23"S 71°33'59"W.
Map:	Map of area around epicenter. Click to open in Google Maps.
Magnitude:	MAG 5.7 Detected by 53 stations. Maximum Error Range ±0.043 .
Depth:	5 km (3 mi) A very shallow depth.
Max. Intensity:	V Moderate On the Modified Mercalli Scale.
Tsunami Risk:	Low tsunami risk Earthquakes under MAG-6.5 do not usually cause tsunami's. Always stay cautious - More info here.

Minimal impact predicted

Based on scientific estimates by the US Geographic Survey (USGS), the risk of high fatalities for this earthquake is classified at level GREEN (low). They expect an 65% likelyhood of between 0 and 1 fatalities, and a 96% chance that the number of fatalities falls no higher than 10.

The USGS classifies the economic impact of this earthquake at level GREEN (low). They expect an 65% likelyhood of between 0 and 1 million US Dollars in economic damage and impact, and a 96% chance that the economic impact of this earthquake falls no higher than 10 million USD.

Roughly 300 thousand people exposed to shaking

This earthquake may have been felt by around 300 thousand people. That is the expected population size of the area exposed to a level of shaking of II or higher on the Modified Mercalli scale according to the USGS.

An estimated 22,410 people were exposed to level IV. At this level, light shaking and likely no damage can be expected. Intensity level III was experienced by the majority of people (around 270 thousand). In their region, weak shaking and probably no damage can be expected.

People in 2 countries have been exposed to shaking. In Chile , around 300 thousand people, with impact levels up to IV (light shaking, likely no damage). People were exposed to shaking in Argentina as well.

People	MMI Level	Shaking	Damage
0	I	Not noticable	None
2,980	II	Very weak	None
272,900	III	Weak	Probably none
22,410	IV	Light	Likely none
0	V	Moderate	Very light
0	VI	Strong	Light
0	VII	Very Strong	Moderate
0	VIII	Severe	Moderate to heavy
0	IX	Violent	Heavy
0	X	Extreme	Very heavy

Nearby towns and cities

This earthquake may have been felt in Chile . The closest significant population center near the earthquake is Copiapó in Atacama, Chile. Copiapó is located 122 kilometer (76 mi) west of the epicenter. Copiapó experienced an earthquake intensity (MMI Scale) of roughly III. That level implies weak shaking and probably no damage.

Multiple large cities are in proximity of today's earthquake. Copiapó is located 122 km to the east and experienced an intensity of III (weak shaking, probably no damage). Coquimbo is located 295 km to the south (intensity unknown, possibly low). La Serena is located 291 km to the south (intensity unknown, possibly low).

The table below provides an overview of all places in proximity of today's earthquake. Where available, the estimated intensity on the Modified Mercalli Intensity Scale in each place is included. Places where this information is omitted likely experienced little impact.

Overview of nearby places

Cities and Towns around the epicenter of this earthquake.
Distance	Place	Intensity (MMI)
122 km (76 mi) E from epicenter	Copiapó Atacama, Chile.	III Weak
162 km (101 mi) SSE from epicenter	Vallenar Atacama, Chile.	III Weak
182 km (113 mi) NE from epicenter	Diego de Almagro Atacama, Chile.	III Weak
291 km (181 mi) S from epicenter	La Serena Coquimbo Region, Chile.
295 km (183 mi) S from epicenter	Coquimbo Coquimbo Region, Chile.

Earthquake Intensity Map

The maximum intensity (MMI Scale) caused by this earthquake is IV. The map below shows in which areas this earthquake was the most and least impactful. It is based on data from the US Geographic Survey.

I Not felt

II Weak

III Weak

IV Light

V Moderate

VI Strong

VII Very Strong

VIII Severe

IX Violent

X Extreme

Earthquake Intensity Map based on Shakemap Data provided by USGS.

9 Aftershocks detected

After this earthquake struck, 9 smaller aftershocks occurred. Just 1 day after this main shock, an earthquake measuring MAG-4.5 was detected 34 km (21 mi) north-northeast of this earthquake.

Before this earthquake struck, 4 smaller foreshocks occurred. A 4.5 magnitude earthquake hit 2 days earlier nearby.

Overview of foreshocks and aftershocks

Detected MAG2.5+ earthquakes within within 100km (62 mi), that occurred in the three days before and after the main shock.
Classification	Magnitude	When	Where
Foreshock	M 3.0	3 days earlier Sep 13, 2023 00:47 (Santiago Time)	41 km (25 mi) ENE from Main Shock.
Foreshock	M 4.5	2 days earlier Sep 13, 2023 21:50 (Santiago Time)	44 km (27 mi) ENE from Main Shock.
Foreshock	M 3.5	1 day earlier Sep 14, 2023 09:20 (Santiago Time)	46 km (29 mi) E from Main Shock.
Foreshock	M 4.4	1 day earlier Sep 14, 2023 11:40 (Santiago Time)	42 km (26 mi) ENE from Main Shock.
Main Shock This Earthquake	M 5.7	Sep 15, 2023 15:07 (Santiago Time)	-
Aftershock	M 3.6	13 hrs later Sep 16, 2023 04:18 (Santiago Time)	48 km (30 mi) NE from Main Shock.
Aftershock	M 2.6	15 hrs later Sep 16, 2023 05:48 (Santiago Time)	55 km (34 mi) NE from Main Shock.
Aftershock	M 2.6	16 hrs later Sep 16, 2023 06:39 (Santiago Time)	56 km (35 mi) NE from Main Shock.
Aftershock	M 2.8	16 hrs later Sep 16, 2023 07:05 (Santiago Time)	50 km (31 mi) NE from Main Shock.
Aftershock	M 4.5	1 day later Sep 17, 2023 00:17 (Santiago Time)	34 km (21 mi) NNE from Main Shock.
Aftershock	M 3.1	2 days later Sep 17, 2023 17:28 (Santiago Time)	52 km (33 mi) NE from Main Shock.
Aftershock	M 2.7	2 days later Sep 17, 2023 18:49 (Santiago Time)	46 km (29 mi) NE from Main Shock.
Aftershock	M 3.4	2 days later Sep 17, 2023 19:25 (Santiago Time)	57 km (35 mi) NE from Main Shock.
Aftershock	M 3.3	3 days later Sep 18, 2023 03:29 (Santiago Time)	12 km (7 mi) E from Main Shock.

More earthquakes coming?

Earthquakes can create aftershocks. These are generally at least 1 magnitude lower than any main shock, and as time passes the chance and strength of aftershocks decreases.

The chance that a significant earthquake like this one is followed by an even larger earthquake is not so large. On average, scientists estimate a 94% chance that a major earthquake will not be followed by an even larger one. It is still adviced to be aware of this risk

Read: How to Stay Safe during an Earthquake (cdc.gov).

Earthquakes like this happen often in the region

Earthquakes of this strength are very common in the region. This is the strongest earthquake to hit since April 4th, 2023, when a 5.9 magnitude earthquake hit 61 km (38 mi) further east-southeast. An even stronger magnitude 6.9 earthquake struck on November 11th, 2015.

In total, 19 earthquakes with a magnitude of 5.7 or higher have been registered within 300km (186 mi) of this epicenter in the past 10 years. This comes down to an average of once every 6 months.

Low tsunami risk

DISCLAIMER: We strongly suggest to closely monitor advice from local authorities with regards to tsunami risks. Our analysis is based on automatically collected data from external sources, and these might contain mistakes. In addition, earthquakes can cause landslides that may lead to a tsunami, or be a followed by another, potentially stonger, earthquake.

Based on early data it appears this earthquake was not strong enough (lower than MAG-6.5) to be likely to cause destructive tsunami's. However this earthquake appeared to have hit at a shallow depth under sea, so stay cautious and monitor advice from local authorities.

Tsunami Risk Factors

Factor	Under Sea?	MAG-6.5 or stronger?	Shallow depth?
Explanation	Almost all tsunami's are caused by earthquakes with their epicenter under sea or very near the sea. However stay cautious in coastal areas as earthquakes on land may cause landslides into sea, potentially still causing a local tsunami.	Under MAG 6.5: Very unlikely to cause a tsunami. MAG 6.5 to 7.5: Destructive tsunami's do occur, but are uncommon. Likely to observe small sea level changes. MAG 7.6+: Earthquakes with these magnitudes might produce destructive tsunami's.	Most destructive tsunami's are caused by shallow earthquakes with a depth between 0 and 100km under the surface of the earth. Deeper tsunami's are unlikely to displace to ocean floor.
This Earthquake	This earthquake appears to have struck under the sea.	Not this earthquake. This earthquake had a magnitude of 5.7. Earthquakes of this strength are unlikely to trigger a tsunami.	This earthquake occurred at a depth of of 5 km (3 mi). Earthquakes this shallow could trigger a tsunami.

Sources

Last updated 14/11/23 08:18 (). This article is automatically generated based on available data. We keep checking multiple sources for additional information. This article gets updated as new details on this earthquake become available.